The spine is formed of superposed vertebrae, normally aligned along a vertebral axis, from the lumbar vertebrae to the cervical vertebrae, each having a posterior wall from which projects a spinous process and two lateral edges from the walls of which there project ribs and/or transverse processes and/or lamina. If the spine of a person has abnormal curvature, the vertebrae are typically inclined relative to one another and relative to the vertebral axis.
In order to straighten the vertebral column as a remedy for this situation, the lateral edges of the vertebrae on the concave side can be moved away from one another and supported at distances from one another substantially equivalent to the distances between the lateral edges on the other side. Devices known in the art for holding the vertebrae relative to one another include rods that are held by rod-receiving elements attached to the vertebrae, for example using screws, hooks, or flexible ligatures.
The assembly of the rods to the rod receiving elements is normally carried out, in the operating theatre, after the rod-receiving elements have been surgically anchored to an osseous structure of the patient. It is therefore a delicate operation requiring significant skill. In order to facilitate it, it is known in the art to use specialised surgical instruments, such as a so-called persuader, which is a surgical instrument comprising an elongate member with, at a first end, a device for holding the rod substantially transversally to the elongate member. While such a persuader is adequate for pushing the rod in the direction of the elongate member, it is less useful for translating the rod laterally, that is, perpendicularly to both this elongate member and the rod. This is a significant drawback in particular when the rod-receiving elements are not top- but side-loading, and therefore require a lateral translation of the rod to properly engage it.
Another surgical instrument has been proposed, which is sold by Medtronic under the trade name CD Horizon® Legacy™ 5.5 Translator Rod Pusher, and comprises comprising an elongate member with a support for engaging a rod receiving element, and a hinged connection between the support and the elongate member. The elongate member comprises, at its distal end, a device for holding a rod to be introduced into the rod-receiving element.